Erasable colored pencil lead
US6011084A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 26, 1998 |
| Grant date | Jan 4, 2000 |
| Priority date | — |
| Expiry date | Jun 26, 2018 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09D13/00
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
The present invention provides a colored pencil lead composition comprising a colorant, one or more binder resins, a fibrillatable or fibrillated material, a non-fibrillatable particulate lubricant, and a filler. An example of a suitable binder resin is high density polyethylene, and an example of a fibrillated or fibrillatable material is fibrillatable polytetrafluoroethylene. An example of a non-fibrillatable particulate lubricant is micronized polytetrafluoroethylene. The colored pencil lead of the present invention produces marks on paper which are easily erased by ordinary pencil eraser. The present invention further provides a process for preparing the colored pencil lead of the present invention comprising compounding the colorant, the binder resin or resins, the fibrillatable or fibrillated material, the non-fibrillatable particulate lubricant, and the filler to obtain a blend and forming the pencil lead from the blend.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.